Analysis of the profile of T CD4 + cytotoxic and senescent lymphocytes in patients during the clinical evolution of COVID-19

• Grant number: 19/25788-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2020
• End date: February 28, 2021
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Alessandro dos Santos Farias
• Grantee: Sophia Nora Baptista
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

COVID-19 is an emerging disease, caused by the SARS-CoV-2 virus, which has become pandemic in recent months. Several studies have shown that the number of T lymphocytes in patients infected with SARS-CoV-2 is drastically reduced. The impairment of lymphocyte activity can be fundamental for the quality of the response against SARS-CoV-2, being characterized as a possible escape mechanism of the virus. In the case of CD8 + T lymphocytes, early exhaustion and / or low activity can directly compromise the antiviral activity of these cells. In parallel, the impairment of CD4 + T lymphocyte activity would represent a very important deficit in the adaptive response in general. Interestingly, some patients already recovered from COVID-19 have undetected levels of antibodies. In this context, it is possible that SARS-CoV-2 infection directly (lymphocyte infection) or indirectly compromises the quality of the adaptive immune response. Still, in recent years, several studies have demonstrated the cytotoxic capacity of CD4 + T lymphocytes, mainly in pathological conditions. In several viral infections such as EBV, LCMV, INFLUENZA, DENGUE, among others, T CD4+ cytotoxic cells are of crucial importance in resolving the infection. In this context and understanding the urgency of the present moment, our intention in this proposal is to investigate the occurrence of T CD4+ cytotoxic and senescent lymphocytes in patients diagnosed with the moderate or severe symptomatic forms of COVID-19. Possible different patterns in these populations could predict a better or worse evolution of the disease, as well as the formation of protective immunity. (AU)